A known interior material, such as a ceiling material of a vehicle and an interior wall finishing material of a house, includes ones having a structure containing a base material and a skin material laminated thereon through an adhesive.
For example, a ceiling material of a vehicle, such as a car and a train, contains: a base material formed of a resin molded material, a corrugated fiberboard or the like; a cushioning material formed of foamed polyurethane, nonwoven fabric or the like, which has been laminated between the base material and a skin material by pressing with adhesive interposed between these materials; and the skin material formed of a woven fabric, a knitted fabric or the like. The cushioning material intervening between the base material and the skin material enhances the ornamental appearance and the texture of the ceiling material of a vehicle.
According to the trend of decreasing the environmental load and saving the energy in recent years, however, there is a demand of an interior material having a structure that contains a base material and a skin material laminated directly thereon without a cushioning material, and a skin material suitable for the structure is demanded.
In view of the demand, for example, JP-A-2005-068577 discloses a ceiling material of a vehicle having a base material layer and a skin material layer laminated on each other, in which a cloth having a raised back surface is used as the skin material, and the back surface of the cloth is adhered directly to the base material layer. In particular, there is disclosed that the cloth has a thickness of from 1.0 to 8.0 mm and an air permeability of from 5 to 150 cm3/cm2·sec, and has a raised part formed of fibers having a thickness of from 0.5 to 5 dtex and fibers having a thickness of from 3 to 20 dtex, and a tricot knitted fabric shown as one example thereof has a soft touch with cushioning property, is of light weight, is excellent in sound absorbency, and thus is favorably used as a skin material of a ceiling material of a vehicle.
JP-A-2005-068577 discloses a technique using a tricot knitted fabric having a single layer structure as the skin material, which nevertheless causes a problem that oozing out of the adhesive would not be sufficiently prevented from occurring, and thus the ornamental appearance and the touch of the skin material are impaired.
To cope with the problem, for example, JP-A-2009-262407 discloses an interior skin material formed of a three-dimensional knitted fabric that contains a knitted front surface part, a knitted back surface part and a front-back connecting part having connecting yarns that connect the knitted front surface part and the knitted back surface part; the interior skin material is able to be adhered by itself onto a base material without necessity of laminating and adhering an intervening member; and after being adhered onto the base material, excellent ornamental appearance is achieved without appearance failure due to the oozing out of adhesive, and sufficient cushioning property is provided. In particular, it is described that, if an interior skin material has an intermediate load of from 1 to 300 N/inch at a stretch rate of 20% upon measuring in the tensile strength test according to JIS L 1018, the interior skin material is excellent in followability to a base material and thus can be easily molded and adhered to a base material even when the base material has a curved surface, thereby providing an interior skin material having excellent ornamental appearance.
However, JP-A-2009-262407 fails to disclose any specific knitting pattern, of three-dimensional knitted fabric in particular, that provides the skin material of above features. Therefore, it is unclear as to what type of the knitting pattern of the three-dimensional knitted fabric is effective.